000
FXUS64 KOUN 051034
AFDOUN
Area Forecast Discussion
National Weather Service Norman OK
434 AM CST Mon Dec 5 2016
.UPDATE...
&&
.DISCUSSION...
We have issued a Dense Fog Advisory for portions of south central
Oklahoma. Several obs are indicating one quarter mile visibility
now. Weak low level moisture advection may necessitate a
northward expansion into OKC/Norman area. We will monitor trends
and update as needed. Temperatures are near freezing at a few
locations but impacts should be minimal given antecedent warm
conditions.
&&
.PREV DISCUSSION... /issued 358 AM CST Mon Dec 5 2016/
DISCUSSION...
Upper level moisture is streaming northeastward across the area
in advance of an opening/accelerating shortwave trough that will
pass through the region today. Shallow low level moisture and
light winds has resulted in some fog across portions of the area
early this morning. Moisture is expected to deepen throughout the
day and rain will form south of the Red River and overspread
roughly the southeastern one third of the area throughout the day.
Based on the latest model guidance, the precipitation was shifted
slightly further east, generally along and south of Interstate 44.
A cold front is expected to progress across the area later tonight
bringing cooler temperatures and a period of post-frontal
northerly winds of around 15 to 25 mph. Models vary on the amount
and depth of low level moisture that will be present both ahead of
and behind the front. Fog seems possible across the south where
low level moisture will be highest and winds will be light until
the front arrives later in the night.
Colder temperatures are expected Tuesday behind the first front,
but a much cold air mass will follow the second front that is
expected to move through on Wednesday. Models are in better
agreement with the timing of the arrival of the arctic air mass
being Wednesday afternoon. Temperatures may fail to rise above
freezing Wednesday across the north and then fall well into the
teens across much of central and northern Oklahoma Wednesday
night. Subtle lift associated with the main upper trough could be
enough for some light snow across the north, although moisture is
limited. Forecast soundings are drier than previous runs and show
only a thin saturated layer above a dry surface layer and very dry
mid levels. We have lowered probabilities and amounts confining a
couple tenths of accumulation to near the Kansas border.
Medium range guidance differs little on when southerly low level
flow will begin causing warmer temperatures to return. High
temperatures should range from the upper 20s to the mid 30s across
the area Thursday, and then warm to the 40s in many areas on
Friday, and 50s for many locations Saturday. Lee surface pressure
falls and resultant strengthening southerly flow Friday and
Saturday results from increasing westerlies that are quasi-zonal.
Amplification of the flow pattern does not look like it will
occur through early next week so precipitation is not expected.
BRB
&&
.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 54 37 46 30 / 10 10 0 10
Hobart OK 54 36 45 30 / 0 0 0 10
Wichita Falls TX 56 40 50 33 / 20 10 10 10
Gage OK 59 31 42 24 / 0 0 0 10
Ponca City OK 56 34 45 27 / 10 10 0 10
Durant OK 49 43 53 37 / 60 50 10 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...Dense Fog Advisory until 9 AM CST this morning for OKZ027-028-
032-038>047-050.
TX...None.
&&
$$
17/12